Pacific Islands - Online Climate Outlook Forum (OCOF) No. 129

Country Name: Kiribati

TABLE 1: Monthly Rainfall Station (include data period) May 2018

March April Total 33%tile 67%tile Median Ranking 2018 2018 Rainfall Rainfall Rainfall (mm) Total Total (mm) (mm) Beru 44.8 5.3 14.9 38.8 96.5 64.0 10/65 Butaritari 28.7 136.9 - 218.7 328.0 302.5 - Kanton 64.6 113.2 - 49.0 94.8 64.5 - Kiritimati 5.7 - 44.3 37.8 106.4 63.3 37/94 Tarawa 7.1 29.2 42.1 93.7 170.6 141.2 9/69

TABLE 2: Three-monthly Rainfall March to May 2018 [Please note that the data used in this verification should be sourced from table 3 of OCOF #125]

Station Three- 33%tile 67%tile Median Ranking Forecast probs.* Verification* month Total Rainfall Rainfall Rainfall (include LEPS) (Consistent, Near- (mm) (mm) (mm) consistent Inconsistent)?

Beru 65.0 158.0 381.0 264.0 10/62 48/42/10 (23.2) Consistent Butaritari - 779.0 1096.7 942.0 - 45/32/23 (9.2) - Kanton - 128.6 231.5 167.7 - 40/45/15 (11.7) - Kiritimati - 288.7 410.3 324.7 - 43/40/17 (15.1) - Tarawa 78.4 334.8 656.2 503.2 3/69 47/32/21 (12.7) Consistent Period:*below normal/normal/above normal

Predictors and Period used for March to May 2018 Outlooks (refer to OCOF #125):

NINO 3.4 SST Anomalies (2mths: December 2017-January 2018)

*Forecast is consistent when observed and predicted (tercile with the highest probability) categories coincide (are in the same tercile). Forecast is near-consistent when observed and predicted (tercile with the highest probability) differ by only one category (i.e. terciles 1 and 2 or terciles 2 and 3). Forecast is inconsistent when observed and predicted (tercile with the highest probability) differ by two categories (i.e. terciles 1 and 3).

TABLE 3: Seasonal Climate Outlooks using SCOPIC for July to September 2018 Predictors and Period used: NINO 3.4 SST Anomalies (2months: April- May 2018)

Below Median Above Station Median Rainfall Median LEPS Hit-rate (prob) (mm) (prob) Beru 53 176.5 47 16.4 62.3 Butaritari 53 561.0 47 8.3 68.3 Kanton 52 180.8 48 1.2 64.0 Kiritimati 50 71.8 50 -1.5 33.8 Tarawa 55 336.2 45 21.9 72.1

Below 33%ile 67%ile Above Normal Station Normal rainfall rainfall Normal LEPS Hit-rate (prob) (prob) (mm) (mm) (prob) Beru 34 130.7 40 261.6 26 20.1 52.8 Butaritari 34 500.0 36 734.0 30 8.6 50.8 Kanton 35 153.5 35 227.3 30 5.9 46.0 Kiritimati 34 42.4 34 101.7 32 0.2 32.4 Tarawa 37 195.8 39 543.6 24 19.3 48.5

TABLE 4: Seasonal Climate Outlooks using POAMA2 for July to September 2018

Lower 33%ile Middle 67%ile Upper Station Tercile rainfall Tercile rainfall Tercile (prob) (mm) (prob) (mm) (prob) Tarawa 64 270 30 636 6 Tabuaeran 79 83 16 317 5 Kiritimati 9 75 79 131 12 Kanton 12 111 76 226 12 Butaritari 76 464 18 730 6 Arorae 39 191 56 574 5

Summary Statements Rainfall for May 2018:

Beru and Tarawa recorded below-normal rainfall for the month of May 2018 while Kiritimati recorded normal rainfall for the same month.

Accumulated rainfall for March to May 2018, including outlook verification:

Beru and Tarawa both recorded below-normal rainfall from March to May 2018 accumulated totals. Outlook Verification is consistent for the two stations.

Tarawa ranks the 3rd driest month for March to May 2018 for the 69 years of record.

Outlooks for July to September 2018: 1. SCOPIC:

At Beru, the outlook shows normal as the most likely outcome, with below-normal the next most likely. Above normal is the least likely.

The outlook for Tarawa shows a near-equal likelihood of normal and below-normal rainfall. Above normal is the least likely.

The outlook offers little guidance as the chances of above-normal, normal and below- normal are similar for Butaritari, Kanton and Kiritimati.

Skills in the outlook is low in Kiritimati, Moderate in Kanton and Butaritari, and high in Tarawa and Beru.

2. POAMA:

Tarawa, Tabuaeran and Butaritari favour below-normal rainfall while Kiritimati, Kanton and Arorae favour normal rainfall.

NB: The X LEPS % score has been categorised as follows: Very Low: X < 0.0 Low: 0 ≤ X < 5 Moderate 5 ≤ X < 10 Good: 10 ≤ X < 15 High: 15≤ X < 25 Very High: 25 ≤X < 35 Exceptional: X ≥ 35